What happens when you don't get any sleep at all?

My sleep patterns are really, really weird and chaotic, no thanks to my rather high caffeine usage. My body seems to decide that it's time to sleep without any rhyme or reason; sometimes, I'll be sitting in class or at the computer just a few hours after a good night's sleep, and I'll suddenly feel very tired. OTOH, as of right now, I've been up for almost two days straight, and I'm much more energetic than usual right now. o_o

something tells me that I'll probably sleep all day tomorrow, classes be damned.

For some reason, if I stay up for more than a day straight or so, I start to feel much hungrier than usual for some reason. My speech and writing become a bit unfocused and wordy, but I'm usually guilty of that even when I'm well-rested. ^^;

Jam it back in, in the dark.